Bump actions/cache action to v6

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/dependency-check.yml

@@ -26,7 +26,7 @@ jobs:
         with:
           maven-version: 3.9.16
       - name: Cache the NVD database
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.m2/repository/org/owasp/dependency-check-data
           key: dependency-check